An anonymous reader writes "Spammers are back with a new trick, this time round sending messages with MP3 attachments that contain the latest pump-and-dump stock scams. One sample identified by Sophos was a heavily distorted 30-second MP3 file. A synthetic female voice was used to promote a particular stock. Says Graham Cluley, senior technology consultant at Sophos: 'Although the spammers seem to have a fair bit to learn about machine-generated sales patter, some companies might consider blocking all MP3s in email as a matter of course. So many music files infringe copyright, and it can be hard for a company to establish which ones are legal and which are not after they have arrived. Blocking MP3s, or at least quarantining until requested by the user, can be a good way for a company to take a proactive stance against the use of email for illegal file sharing. It also has the benefit of neutralizing this sort of spam at the same time.'"